Factors affecting various biomarkers in untreated lung cancer patients and healthy donors.

The purpose of the present communication was to determine in lung cancer patients and healthy donors if there was a possible association between cancer and biomarkers of cytogenetic damage and ras p21 oncoprotein levels, and if various exogenous confounding factors (such as smoking habit) and endogenous ones (age, sex, etc.) could affect these biomarkers. Peripheral blood and plasma were collected from 31 lung cancer patients prior to treatment and 35 healthy donors of a similar socioeconomic status and from the same region in Poland. Chromosomal aberrations (CA), sister chromatid exchanges (SCE), high frequency cells (HFC), and proliferative rate index (PRI) were examined from the blood and ras p21 oncoproteins from the plasma. These parameters were used as biomarkers of genotoxic anomalies. All the biomarkers were examined for their relationship to confounding factors of age, sex, smoking habit, and immediate family cancer history. Results were analyzed by a t-test, analysis of variance (ANOVA), and stepwise multivariate regression analysis. All types of CA (including and excluding gaps), percent aberrant cells, SCE, and ras p21 oncoproteins were statistically significantly higher in cancer patients than in the healthy donors. Although there were smaller numbers of females in the cancer patients group who were older than the males, there was a difference due to sex (gender) with statistically significant increases in females for CA, SCE, and HFC, but there was no increase for ras p21 oncoproteins. Cytogenetic damage was not related to other cancers in the immediate families of the groups. All major CA parameters differed significantly between smokers and non-smokers in the cancer patients group, and SCE and HFC differed in the healthy donors group. Such parameters also showed a significant variability with the number of cigarettes smoked and the years of smoking habit. Multivariate regression analyses showed a significant association between cytogenetic damage, ras p21 oncoproteins, and cancer. In conclusion, cytogenetic damage and ras p21 oncoproteins in this study appear to be biomarkers associated with cancer, but have not been proved causally, and confounding factors such as age, sex (gender), and smoking can have an impact on them.